The line of 6000 Vikings are very good and sew a vvery nice straight stitch. Most of them have to be oiled and are not self oiling. The first thing I would do is clean it up, disamble the bobbin area and clean it out good. Oil all areas that need oiling. You will be surprised how good it will move when oiled. Do not forget the bottom of the machine. Lay it on its side and take it apart at the bottom area. Lay some cardboard down to keep oil from going everywhere. I have a 6460 Viking and I did this to it. If the top comes off oil it, flip open where the needle bar goes up and down, oil it. Place oil in the hole where you adust the pressure of the foot. Good luck.